Method of filling porosity of ceramic component

Abstract

A method of fabricating a ceramic component includes initially partially filling pores of a porous structure using one of a first processing technique or a second, different processing technique to form a preform body with residual porosity. The first processing technique produces a first ceramic material in the pores of the porous structure and a second processing technique produces a second ceramic material in the pores of the porous structure. When the first processing technique is used to initially partially fill the pores of the porous structure, the second processing technique is used thereafter to at least partially fill the residual porosity with the second ceramic material. When the second processing technique is used to initially partially fill the pores, the first processing technique is used thereafter to at least partially fill the residual porosity.

What is claimed is: 
     
       1. A method of fabricating a ceramic component, the method comprising:
 initially partially filling pores of a porous structure using one of a first processing technique or a second, different processing technique to form a preform body with residual porosity, the processing techniques differing with respect to the way that ceramic precursors are delivered into a green state and formation mechanisms of final ceramic materials from the ceramic precursors, the first processing technique producing a first ceramic material in the pores and the second processing technique producing a second ceramic material in the pores that is different from the first ceramic material in at least one of composition, microstructure and physical property; 
 when the first processing technique is used to initially partially fill the pores of the porous structure, thereafter performing the second processing technique to at least partially fill the residual porosity with the second ceramic material; and 
 when the second processing technique is used to initially partially fill the pores of the porous structure, thereafter performing the first processing technique to at least partially fill the residual porosity with the first ceramic material. 
 
     
     
       2. The method as recited in  claim 1 , wherein the first ceramic material is crystalline and the second ceramic material is amorphous glass. 
     
     
       3. The method as recited in  claim 1 , wherein the porous structure includes coated fibers. 
     
     
       4. The method as recited in  claim 1 , wherein a total void volume after the first processing technique and the second processing technique is less than 1 volume percent. 
     
     
       5. The method as recited in  claim 1 , including initially partially filling the pores using the first processing technique and, prior to performing the second processing technique, repeating the first processing technique to control the residual porosity to be within a predetermined range of 20-43 volume percent of the preform body. 
     
     
       6. A method of fabricating a ceramic component, the method comprising:
 initially partially filling pores of a porous structure using one of a first processing technique or a second processing technique to form a preform body with residual porosity, the processing techniques differing with respect to the way that ceramic precursors are delivered into a green state and formation mechanisms of final ceramic materials from the ceramic precursors, the first processing technique including infiltration with a preceramic polymer material and thermal treatment to convert the preceramic polymer material to a ceramic material and the second processing technique including infiltration with a heated, liquid glass or glass/ceramic material and solidification of the liquid glass or glass/ceramic material to a solid glass or glass/ceramic material; 
 when the first processing technique is used to initially partially fill the pores of the porous structure, thereafter performing the second processing technique to at least partially fill the residual porosity with the solid ceramic glass material; and 
 when the second processing technique is used to initially partially fill the pores of the porous structure, thereafter performing the first processing technique to at least partially fill the residual porosity with the ceramic material. 
 
     
     
       7. The method as recited in  claim 6 , including initially partially filling the pores using the first processing technique. 
     
     
       8. The method as recited in  claim 6 , including initially partially filling the pores using the second processing technique. 
     
     
       9. The method as recited in  claim 6 , wherein the residual porosity is interconnected. 
     
     
       10. The method as recited in  claim 6 , wherein the residual porosity is no greater than approximately 43 volume percent of the preform body. 
     
     
       11. The method as recited in  claim 6 , wherein the residual porosity is 20-43 volume percent of the preform body. 
     
     
       12. The method as recited in  claim 6 , wherein a total void volume after the first processing technique and the second processing technique is less than 1 volume percent. 
     
     
       13. The method as recited in  claim 6 , wherein the ceramic material includes filler particles selected from a group consisting of silicon carbide, aluminum nitride, boron carbide, refractory materials, boron nitride, diamond and combinations thereof. 
     
     
       14. The method as recited in  claim 6 , including a final composition, by volume percentage, of:
 20-70 of the porous structure, 
 1-12 of a coating on the porous structure, 
 1-75 of the ceramic material, and 
 a balance of the solid glass or glass/ceramic material and residual void volume, wherein the residual void volume is less than 5 volume percent. 
 
     
     
       15. The method as recited in  claim 14 , wherein the final composition includes:
 30-50 of the porous structure, 
 2-5 of the coating, 
 25-65 of the ceramic material, and 
 a balance of the solid glass or glass/ceramic material and the residual void volume. 
 
     
     
       16. The method as recited in  claim 6 , including initially partially filling the pores using the first processing technique and, prior to performing the second processing technique, repeating the first processing technique between two and nine times to control the residual porosity to be within a predetermined range.